In hindsight, the biggest red flag waving above Tamerlan Tsarnaev was the request from Russian Security agents that the FBI question him about how radical he was.

Several members of Congress said the FBI should have kept an eye on him instead of closing the file.

But FBI agents said they found nothing amiss.
The rules say you can't just start tailing a legal resident who hasn't done anything wrong yet. Possibly harboring radical feelings isn't a crime.

Plus - we can be pretty sure Tamerlan wasn't the only guy to pop up on the FBI's religious zealot radar. My guess is there are thousands. That's a lot of following to do.

But what about the other red flags - friends and family saying he was getting more religious, more conservative, more combative - at one point getting in an Imam's face for preaching about Martin Luther King Jr., which Tamerlan thought was wrong because King wasn't a Muslim.

Would that, combined with his extended visit to relatives in South Russia, be enough to warrant surveillance?

Maybe, except that in America you are free. Free to travel, free to worship - free to become an ultra-conservative, free to say mean things about Martin Luther King, Jr. - without the government hassling you. You are also free to go on the internet and download bomb-making plans.

A lot of people can't believe they didn't have outside help. I can see why. Because if they pulled this off alone, it means countless others could do the same. Countless others and find everything they need without help from shady people who turn out to be undercover FBI agents. And that is not a happy thought.